Five-fluorouracil (5-FU) is an effective chemotherapeutic medication. It is commonly implicated in treatment of various malignancies; this research aimed to investigate potential therapeutic effect of the BMMSCs and Astaxanthin on 5-FU toxic effect on albino rat's stomach. 40 rats were divided into 4 groups: Group I (control group): received no treatment Group II (5-fluorouracil group): for 5 consecutive days rats were intravenously injected by 50 mg/kg 5-FU. Group III (5-Fluorouracil group and Astaxanthin): got 5-FU as in group II, followed by astaxanthin 50mg/kg for 10 consecutive days. Group IV (BMMSCs): received 5-FU as in group II then intravenously injected by 10⁶ of BMMSCs once in rat tail. All rats were sacrificed on the 35^th day from the beginning of the experiment, to be examined microscopically, stomach sections were stained by H&E to evaluate histopathological changes, stained also with PAS to evaluate mucosal glycoprotein production, transmission electron microscopic was used to evaluate ultra-structural changes and Immunohistochemistry using Ki67 was used to evaluate level of cell proliferation. examination of stomach Sections of group II showed separation in the gastric glands, congested blood capillary, vacuolations of parietal cells, while (Gr III) and (Gr IV) showed marked stomach histological structure improvement and down regulated expression of Ki67, compared to the (GrII). Electron microscope supported these results. Both BMMSCs and Astaxanthin have good impact in ameliorating the toxic effect of 5-FU on albino rats stomach, with no significant difference between both techniques.